Pendent sprinkler



Feb.'3,'1959 I G. A. BRAY PENDENT SPRINKLER 5 sheets -sheet 1 Filed June15, 1956 INVENTOR. GEDDES ALAN BRAY ATTORNEY Feb. 3, 1959 G. A. BRAY 2,

PENDENT SPRINKLER Filed June 15; 1956 s Sheets-Sheet 3 Jaw 510? INVE R.-

GEDDES ALAN BR FIG. 5

ATTORNEY United States Patent O PENDENT SPRINKLER Geddes Alan Bray, NewMoston, Manchester, England assignor to Grinnell Corporation,Providence, R. 1., a corporation of Delaware Application June 15, 1956,Serial No. 591,579

8 Claims. (Cl. 169-37) 'This invention relates to automatic sprinklersystems of the so-called dry pipe type. More particularly it has to dowith such systems in which a plurality of pipes carrying thermallyactuated sprinkler heads at their lower ends have their upper endsconnected to a supply or distributing pipe in spaced relation therealongand extending downwardly therefrom.

Some locations which are required to be served by fire extinguishingsprinkler systems are subject to low temperatures which would freeze thefire extinguishing medium (usually water) and render the systeminoperative if the supply pipes distributed throughout the location werenormally filled with this medium. To overcome this problem it has beencustomary to provide a valve at the source of supply of the medium, forexample in a single heated room where the connection to a city watermain emerges from the ground, which valve prevents the water fromentering the distributing pipes until a fire occurs. Thus, a commonarrangement is to fill the distributing pipes with air under pressureand provide a valve which this air pressure serves to keep closed. Thenby thermal actuation the sprinkler heads open, the air is releasedthrough these open heads and the valve opens allowing water to flow intothe distributing pipes to be discharged from the same open heads.

In most sprinkler systems the distributing pipes with which thesprinkler heads are associated extend horizontally throughout thelocation to be served, for example near the ceilings of enclosures, andit is frequently desirable or necessary to have some or all of thesprinkler heads mounted on the lower ends of lengths of generallyvertical pipe (hereinafter called drop pipes) which have their upperends connected to the horizontal pipes. This would be the arrangement,for example, where a false ceiling is employed through which only thesprinkler heads extend, the pipes above being concealed.

In such arrangements, however, if there is a fire or if water isintroduced into the distributing pipes to test the system, while thewater which would fill the horizontal pipes could be readily drained toreset the system after the fire is extinguished or the test concluded,any water which entered the unactuated sprinkler heads and downwardlyextending drop pipes connecting the same to the horizontal pipes couldonly be drained by removing each such head.

To avoid such individual draining of each pendent sprinkler head,various arrangements have been proposed whereby the water is preventedfrom entering the drop pipes of unactuated sprinkler heads and wherebysprinkler head actuation permits such entry. For example, one

arrangement has been proposed having at the upper end of the drop pipe avalve, spring biased to open but normally latched closed by a directmechanical connection extending to the unactuated sprinkler head. Inanother earlier arrangement a frangible member which normally closes theupper end of the drop pipe is shattered by a spring loaded plungerreleased by sprinkler head actuation.

Patented Feb. 3, 1959 The present invention has the advantage ofemploying a smaller number of parts than these previous proposals. Thusa dry pendent sprinkler is provided which in gen eral comprises a droppipe sealingly closed at its lower end by the usual sprinkler head andsealingly closed at its upper end with a flexible diaphragm to form achamber which is substantially filled with a non-freezing liquid. Aslong as the sprinkler head remains unactuated and sealingly closes thelower end of the drop pipe the diaphragm is supported against pressuresin the distributing pipe by the incompressible non-freezing liquid andperforms its closing function. When the sprinkler head is actuated,however, the lower end of the drop pipe is opened and the non-freezingliquid flows therefrom, the diaphragm is then no longer supported by thenon-freezing liquid and the greater pressure in the horizontal pipedestroys the seal provided by the diaphragm.

Accordingly it is an object of this invention to provide a drop pipe ofan automatic sprinkler system with improved seal means at its upper endwhich will assure the entry of a fire extinguishing medium into onlythose drop pipes whose sprinkler heads have been actuated.

Another object of this invention is to provide a seal for, and anon-freezing liquid in, a drop pipe of an automatic sprinkler system,the seal and liquid cooperating with each other to function as a one-wayvalve which prevents this non-freezing liquid from entering the systembut which permits the passage of a fire extinguishing medium when thesprinkler head of that drop pipe is actuated.

Another object of this invention is to provide a drop pipe of anautomatic sprinkler system with a seal and a non-freezing liquid, whichliquid will support the seal against pressures in the system.

Another object of this invention is to provide a seal at the upper endof a drop pipe in an automatic sprinkler system which will prevent themixing or difiusing of a non-freezing liquid in the drop pipe with waterin the system.

Another object of this invention is to provide a seal means in a droppipe for an automatic sprinkler system,

which seal means include a stud and a flexible diaphragm embracing thestud when the sprinkler head associated with the drop pipe is unactuatedand which diaphragm will slide off the stud and open the seal means whenthe associated sprinkler head is actuated.

Another object of this invention is to provide an apertured flexiblediaphragm which functions as a seal for a drop pipe in an automaticsprinkler system wherein the aperture is provided with an upstandingcollar slidably fitting around a stud and wherein the portion of thediaphragm adjacent the collar normally has an upward slope.

Another object of this invention is .to provide an apertured flexiblediaphragm which functions as a seal for a drop pipe in an automaticsprinkler system wherein the aperture fits around a stud and whereinsubstantial displacement of the diaphragm relative to the stud isneces-' ary to disrupt the seal.

In the drawings:

Figure 1 is an end elevation view of a drop pipe arrangement inaccordance with the present invention with portions shown in crosssection and with the diaphragm in sealing position;

Figure 2 is a side elevation view of the arrangement of Fig. 1;

Figure 3 is a cross section plan view taken on line 3-3 of Fig. 1;

Figure 4 is a cross section plan view taken of Fig. 1;

Figure 5 is fragmentary view like Fig. l, but showing the diaphragm inopen position; and

Figure 6 is a perspective view of the diaphragm.

onsline 4-4 Referring now to the drawings, wherein like numerals denotelike parts throughout, denotes a fitting in a supply or distributingpipe 11 which is normally filled with a gas (for example, air) underpressure. A threaded aperture 12 is provided in the fitting 10 intowhich is threaded a plug 14 having its own aperture 16. The top of theplug 14 is provided with a plurality of angularly spaced inclined legs18 which terminate in a collar 20. A downwardly extending cylindricalstud 22 has its upper end secured within the collar by a pin 24.

A drop pipe 26 having a separable flange 28 at its upper end is securedto the plug 14 by a plurality of bolts 30 and nuts 31. A gasket may beplaced between the fitting 10 and plug 14. At its lower end, this droppipe is provided with a thermally actuated sprinkler head 32 whichnormally sealingly closes the lower end of the drop pipe but which, whenactuated, opens this lower end. There are a number of sprinkler headsnow on the market which may be used, inasmuch as this invention isindependent of the particular type employed.

Clamped at its periphery between the plug 14 and the drop pipe flange 28is an apertured impervious flexible sleeve or diaphragm 34. Theperiphery of the aperture is preferably provided with a lip portion 36which slidably embraces a portion of the stud 22. A fluid 38, such asglycerine, having a freezing point below those temperatures normallyencountered in nature and hereafter called the non-freezing liquid,substantially fills the chamber defined by the diaphragm, stud, droppipe, and sprinkler head. For convenience in filling this chamber withthe non-freezing fluid, the drop pipe flange 28 may be provided with ahole 40 and plug 42.

Such filling is done initially by assembling the unit comprising plug14, flange 28, drop pipe 26 and sprinkler head 32 and disposing thisunit on its side with the hole 40 uppermost. When filling is completedthe plug 42 is threaded into place to close hole 40 and the unit issecured to the fitting 10 by threading the plug 14 into the aperture 12.In an automatic sprinkler system a plurality of such units are securedin the supply pipe 11 at spaced intervals whereby the pipe may supply afire extinguishing medium to any drop pipe or pipes whose sprinklerheads have been actuated. The main part of the device may be hidden by afalse ceiling 44, in which case an opening 45 is provided therein ateach such device whereby the unit may be threaded into aperture 12 frombelow the false ceiling 44, for example with a special tool in thenature of a box wrench. A ceiling plate 45a serves to cover the opening45 in such a false ceiling after the unit is installed.

The operation of the device is as follows:

If all of the sprinkler heads are unactuated, the gas (air) pressure inthe fitting 10 will exert force against the diaphragm 34 tending to movethe diaphragm off of the stud 22. If the chamber is completely filledwith the non-freezing liquid, the diaphragm will not be so moved by thisforce because the liquid is substantially incompressible. If thenon-freezing liquid does not completely fill the chamber there will bean air space S at the top of the liquid. Then the air pressure in thefitting 10 will cause the side portions of the diaphragm adjacent thelip 36 to collapse slightly about the stud 22 and as these portionscollapse the space S diminishes in volume until the pressure of the airwithin space S equals the pressure in the fitting 10 and no furthermovement of the diaphragm can take place.

As shown in the drawings, the angle between the longitudinal axis of thestud 22 and the major portion of the diaphragm is substantially lessthan ninety degrees. If this angle were in the order of ninety degrees,the arrangement would have to be such that a slight displacement of thediaphragm would result in its sliding 01f the stud in order to make thedevice function. This would be undesirable if the air space S ispresent, the diaphragm must be able to move slightly, as noted, with- 4out leaving the stud to make the pressure within S equal to the pressurein the fitting 14 If the sprinkler head 32 is actuated, it will open andthe non-freezing liquid will flow from the drop pipe. Then the pressurewithin the chamber will drop below that of the air in the fitting 1.0.Then the air pressure in the fitting 10 will exert enough force to movethe diaphragm off the stud 22 and the diaphragm will assume aconfiguration like that shown in Fig. 5. The air in the fitting 10 willnow escape through the drop pipe and consequently the air pressure inthe pipe 11 will drop. This will result in actuation of a valve (notshown) at a water supply station, and water will be admitted to the pipe11. The water will then flow through the fitting 10 and down the droppipe as indicated by the arrows in Fig. 5 and out of the sprinkler head.

After the fiow of water has ceased, as for example when the water How isstopped by a hand operated valve shut off when the fire is extinguished,the pipe 11 is drained of water, the device is reset by removing ceilingplate 45a, unthreading the unit from aperture 12, lowering the unit downthrough the ceiling opening 4-5, again locating the diaphragm on thestud, replacing the sprinkler head, refilling the chamber withglycerine, again threading the unit into aperture 12 through ceilinghole 45 and re placing the ceiling plate. Air under pressure is againintroduced into the fitting 10, and the system is as it was before.

Assume now that some other sprinkler head or heads in another part ofthe system have been actuated and the fitting 10 is again filled withwater. In this case, the pressure of the water, rather than the pressureof the air, will act against the diaphragm. However, the water in thefitting 10 will not enter the drop pipe nor will the non-freezing liquidin the drop pipe mix or diffuse into the water in the fitting 10. Afterthe flow of water has ceased,.the fitting 10 is drained, the drop pipeswhose Sprinkler heads were actuated are removed, reset and re placed asdescribed, and air under pressure is again introduced into the fitting10 and the system is as it was before.

It will be noted that, as shown in the drawings, the sides of thediaphragm snugly engage the interior of the aperture 16 of the plug 14.Thus if the fitting 10 is filled with water, due to the actuation ofanother head or heads in the system, and is subsequently drained, nosubstantial amounts of water (which might later freeze) will remainbetween the diaphragm and the walls of the aperture 16. In addition theclamped periphery of the sleeve or diaphragm 34 is situated only aslight distance below the interior surface of the fitting 10. It isdesirable to make this distance small because when the fitting 10 isfilled with water and subsequently drained, some water may remainbetween the diaphragm and interior of aperture 16. If a large amount ofwater could collect at this point, then if the ambient temperatureshould fall below the freezing point, the ice which would form mighthave a harmful eifect on the subsequent operation of the sleeve ordiaphragm 34. Hence to keep the volume of the liquid which can collectin this space small, so that its effect can be neglected, the clampedperiphery is preferably situated only a short distance below theinterior of the fitting 10.

From the foregoing description and drawings, it will be apparent thatthe operation of the device is not dependent upon the particulararrangement of the diaphragm and stud shown in the drawings. Thus, thestud may be located entirely within the drop pipe or entirely within thefitting or it may extend into both. Similarly the stud may be secured tofixed structure at its end above the diaphragm or at its end below thediaphragm, or both.

I claim:

1. For a supply pipe carrying a fluid under pressure and having anaperture, a pendent device comprising: a drop pipe having one endadapted to be secured to the supply pipe at said aperture, an element atthe said one end of the drop pipe having a portion movable between afirst position in which said element prevents said fluid from passingtherethrough and a second position in which said element allows saidfluid to pass therethrough, closure means at the other end of the droppipe, said drop pipe with the element and closure means at the endsthereof forming a closed chamber when said element portion is in saidfirst position and said closure means is closed, and a non-freezingliquid substantially filling said chamber and supporting said elementportion in said first position against the force exerted by said fluidunder pressure when said closure means is closed, whereby opening ofsaid closure means releases the liquid from the drop pipe and permitssaid fluid under pressure to move said element portion to said secondposition.

2. A device as set forth in claim 1 including a second element andwherein said first recited element cooperates with the second element tomaintain the said element portion in said first position.

3. A device as set forth in claim 2 wherein said first recited elementis an impervious flexible diaphragm having the said portion thereofprovided with an aperture which receives said second element when saidportion is in said first position.

4. A device as set forth in claim 3 wherein said second element is astud and wherein said aperture is provided at its periphery with a lip,the sides of which are substantially parallel to and in engagement withsaid stud when said diaphragm portion is in said first position.

5. A device as set forth in claim 4 wherein said diaphragm portionadjacent said stud lies at an angle to the longitudinal axis thereofwhich is substantially less than 90 when said portion is in said firstposition.

6. In an automatic sprinkler system, in combination; a supply pipehaving an aperture; a drop pipe having one end connected to the saidsupply pipe at the said aperture to form a junction therewith whichpermits the passage of a fluid from the supply pipe to the drop pipethrough the aperture; an element disposed at said junction having aportion movable between a first position in which said element preventsthe flow of a fluid from the said supply pipe to the said drop pipe anda second position in which said element allows the flow of a fluid fromthe said supment portion to assume its second position.

7. In combination, a supply pipe adapted to carry a fire extinguishingmedium, said supply pipe having an aperture; a drop pipe assembly havingone end connected to the said supply pipe at the said aperture to form ajunction therewith which permits the passage of a fluid from the supplypipe to the drop pipe assembly through the aperture; an imperviousflexible sleeve of larger diameter at one end than the other end; theperiphery of the larger end of the sleeve being clamped around the saidaperture between the said supply pipe and said one end of the drop pipeassembly; a cylindrical stud fixed relative to the said junction andhaving one end slidably receiving the smaller end of the said sleeve toclose said aperture; an actuatable normally closed sprinkler head at theother end of the said drop pipe assembly, the sleeve, stud, drop pipeassembly and sprinkler head defining a closed chamber; a non-freezingliquid substantially filling the said chamber, whereby actuation of thesprinkler head allows the non-freezing liquid to flow out of the chamberand thus permit the smaller end of the sleeve to slide off the stud andhence allow a fluid in the supply pipe to flow into the drop pipe.

8. The combination of claim 7 wherein the said clamped portion of thesleeve is only slightly displaced I from the interior surface of thesaid supply pipe, whereby of its periphery and the interior surface ofthe supply pipe.

ply pipe to the said drop pipe; an actuatable sprinkler References Citedin the file of this patent UNITED STATES PATENTS 363,187 Tonge May .17,1887 1,736,256 Doughty Nov. 19, 1929 2,903,150 Tyden Mar. 28, 1933FOREIGN PATENTS 11,956 Great Britain Dec. 31, 1892

